The GERB experiment 1 The Geostationary Earth Radiation Budget (GERB) experiment John Harries, Professor of Earth Observation, Blackett Laboratory

The GERB experiment 2 Contents 1.What’s it all about? 2.What is GERB? 3.European science contributng at the forefront of climate research

The GERB experiment 3 1.What’s it all about? Climate change is a major scientific problem and threat to global stability; We make predictions about how climate might change in future using coupled, ocean-atmosphere General Circulation Models (GCMs); Ultimately the models must be tested and validated against observations of the real world.

The GERB experiment 4 GERB will make the first ever measurements of the Earth’s total energy balance from geostationary orbit. High accuracy measurements of the solar radiation absorbed, and the infrared energy emitted by the Earth will be produced each 15 minutes. GERB About 40 cm

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7 Should we believe “climate change”? Yes! Hadley CentreHarries et al., Nature, March IPCC

The GERB experiment 8 Should we believe that we understand “climate change” well enough to accurately predict our future? No! Feedback processes, especially clouds, water vapour, oceans, cause large uncertainty

The GERB experiment 9 2. What is GERB? (Talk on GERB design in future) GERB is a de-spun (MSG spins at 100 rpm: 18g!!) absolute radiometer seeking to achieve absolute accuracies (target  0.5-1%). High time resolution (15 mins) for first time. Calibration in new facility at IC; GERB-1, -2 and –3 have been designed, built,tested and calibrated; Imperial team: John PI, Steve Manager, Jacqui Project Scientist, Jenny and James Instrument Scientists, Jo George Student. RAL leads technical project. GIST (GERB International Science Team) led by PI includes many world experts in ERB and EO studies.

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11 Array moves one pixel to west on every rotation of MSG, to build up image of 256x256 pixels 256 pixels

The GERB experiment European science at the forefront of climate research (Talks on GERB science in future) Three examples of “Hot topics”: Diurnal cycle of ERB and cloud- climate interaction; Saharan dust; Climate variability and trends.

The GERB experiment 13 Diurnal cycle of ERB and cloud-climate interaction over Africa Afternoon thunderclouds over the Serengeti

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The GERB experiment 15 Pictures!

The GERB experiment 16 5.Pictures from the launch!

The GERB experiment 17 5.Pictures from the launch!

The GERB experiment 18 5.Pictures from the launch!

The GERB experiment 19 5.Pictures from the launch!

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The GERB experiment 21 4.Concluding remarks MSG is a major European initiative to be proud of, in monitoring the Earth’s weather and climate: it contributes to the world effort in this area; Congratulations to all the GERB team at Imperial, RAL, Leicester, NPL, in Italy, Belgium, Germany and USA